Re: [5.10, 5.15] New bpf kselftest failure

Luiz Capitulino
2023-07-17T14:59:31Z

On 2023-07-17 10:55, Eduard Zingerman wrote:

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>
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> On Mon, 2023-07-17 at 09:04 -0400, Luiz Capitulino wrote:
>> Hi,
>>
>> The upstream commit below is backported to 5.10.186, 5.15.120 and 6.1.36:
>>
>> """
>> commit ecdf985d7615356b78241fdb159c091830ed0380
>> Author: Eduard Zingerman <eddyz87@gmail.com>
>> Date: Wed Feb 15 01:20:27 2023 +0200
>>
>> bpf: track immediate values written to stack by BPF_ST instruction
>> """
>>
>> This commit is causing the following bpf:test_verifier kselftest to fail:
>>
>> """
>> # #760/p precise: ST insn causing spi > allocated_stack FAIL
>> """
>>
>
> I can reproduce the error on 6.1.36 but don't understand what's causing it yet.
> The log is suspiciously different from master, will comment later today.

Thank you very much for the prompt reply, Eduard.

I'm available for further testing if needed.

- Luiz

>
>> Since this test didn't fail before ecdf985d76 backport, the question is
>> if this is a test bug or if this commit introduced a regression.
>>
>> I haven't checked if this failure is present in latest Linus tree because
>> I was unable to build & run the bpf kselftests in an older distro.
>>
>> Also, there some important details about running the bpf kselftests
>> in 5.10 and 5.15:
>>
>> * On 5.10, bpf kselftest build is broken. The following upstream
>> commit needs to be cherry-picked for it to build & run:
>>
>> """
>> commit 4237e9f4a96228ccc8a7abe5e4b30834323cd353
>> Author: Gilad Reti <gilad.reti@gmail.com>
>> Date: Wed Jan 13 07:38:08 2021 +0200
>>
>> selftests/bpf: Add verifier test for PTR_TO_MEM spill
>> """
>>
>> * On 5.15.120 there's one additional test that's failing, but I didn't
>> debug this one:
>>
>> """
>> #150/p calls: trigger reg2btf_ids[reg→type] for reg→type > __BPF_REG_TYPE_MAX FAIL
>> FAIL
>> """
>>
>> * On 5.11 onwards, building and running bpf tests is disabled by
>> default by commit 7a6eb7c34a78498742b5f82543b7a68c1c443329, so I wonder
>> if we want to backport this to 5.10 as well?
>>
>> Thanks!
>>
>> - Luiz
>>
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